thesis

Reconsidering the Alternatives
CONCLUSION
Let us return to the metaphysical options enumerated in the introduction in order to see
which remain viable in the face of all that has been said. Firstly, materialism has been elimi-
nated by Chalmers’ supervenience argument – in other words, by the brute, surprising ex-
istence of consciously experienced phenomenology. While the zombie seems logically im-
possible to some, I can only conclude from my own judgement that those people suffer from
either a lack of metaphysical imagination or a dogmatic attachment to materialism.
Although Swinburne’s argument for substance dualism fails, this does not constitute an
argument against the possibility. But substance dualism does run into trouble if we make the
naturalist assumption, for it is difficult to see how scientific laws could bridge events in two
completely separate metaphysical domains. Nonetheless, one could certainly conceive of
such natural laws, however unusual they may seem in comparison to the rest of science.
Idealism, despite its counter-intuitiveness, remains a live option for the broad-minded
naturalist. Nothing about the world as empirically observed rules out the possibility that
‘reality’ is nothing but the interaction and exchange of ideas, sensations and impressions.
However, once one has incorporated the laws of physics into the idealist metaphysic, it is
doubtful whether the resulting picture is distinguishable from neutral monism – by com-
parison, a pure idealism such as that of Berkeley denies the existence of any nomological
causal relationships between events.
For the naturalist, therefore, the most plausible remaining options are property dualism
and neutral monism – that there is a single substance that has either two separate, disjointed
sets of properties or a single set of properties whose nature is yet to be understood. The two
positions differ only over whether physical and phenomenal properties are ultimately re-
ducible to a single unified psychophysical property or not. While neutral monism’s opti-
mism results in a simpler ontological schema, it is left with the problem of explaining how
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